1. Field of the Invention
The present invention relates to an exposure apparatus for intermittently irradiating exposure light from a light source to a subject to be exposed while conveying the subject to be exposed in one direction and forming an exposure pattern, in particular, relates to an exposure apparatus and a photomask for forming two types of exposure patterns requiring different resolutions at the same time in the same exposure process to enhance the efficiency of exposure processing.
2. Description of Related Art
A conventional exposure apparatus intermittently irradiates exposure light to a subject to be exposed which is being conveyed at a constant speed and exposes a mask pattern of a photomask to a predetermined position. The conventional exposure apparatus captures an image of a position on the upstream side of an exposure position of the photomask in the conveying direction of the subject to be exposed by an imaging device, achieves alignment of the subject to be exposed with the photomask on the basis of the captured image, and controls irradiating timing of the exposure light (for example, see Japanese Laid-Open (Kokai) Patent Application Publication No. 2008-76709).
However, such a conventional exposure apparatus transfers a mask pattern formed on the photomask to the subject to be exposed without change by the exposure light vertically passing through the photomask. Therefore, the pattern on the subject to be exposed blurs and the resolution decreases by the presence of a viewing angle (collimation half angle) of light from a light source irradiated to the photomask, so that there is a possibility that a fine pattern is not formed by the exposure. Therefore, two types of patterns requiring different resolutions are not formed at the same time in the same exposure process.
Although it is possible to solve such a problem by dividing the exposure process into two processes in which a fine pattern requiring a high resolution is formed by using, for example, a reduced projection exposure apparatus having a high resolution and a pattern requiring a low resolution is formed by using the above exposure apparatus, there is a problem that the efficiency of exposure processing is low.
It is possible to use the reduced projection exposure apparatus and form two types of exposure patterns requiring different resolutions at the same time in a state in which both exposure patterns have a high resolution. However, in this case, multiple surfaces are exposed while the subject to be exposed is moved step by step in a two-dimensional plane. Therefore, there is a problem that the efficiency of exposure processing is extremely low, in particular, for a subject to be exposed having a large size.